Industrial sewing machine adapter



April 17, 1962 Filed Oct. 21, 1958 H. J. SMITH, SR INDU STRIAL SEWING MACHINE ADAPTER 2 Sheets-Sheet 1 IN V EN TOR. HENRY J. SM|TH,SR., DECEASED BY HENRY J. SMITH EXECUTOR H. J. SMITH, 5R

INDUSTRIAL SEWING MACHINE ADAPTER April 17, 1962 m h w E m A, V 0 QU w w E mzj .1 mm N & mm TE m m m m .w. 0mm 9. N S T 1.. WT T w MM fi 2 m m- E WH MN 0 Filed Oct. 21, 1958 ited States This invention relates to an adapter for an industrial sewing machine, and more particularly relates to a device for automatically starting the sewing operation when the work is fed therein and simultaneously stopping the machine and cutting heavy gauge thread when the stitch has been completed. This invention is especially concerned with the production sewing of a line of heavy stitches across the south of bags to act as a closure therefor. Heretofore, heavy paper and fabric bags for containing fertilizer, potatoes, sugar and the like, were firstfilled with the respective contents and transported in a conveyor line to a sewing machine which was started by hand by an operator for the sewing of a line of heavy gauge stitches across the mouth of the bag. After the bag was sewn closed, the operator would stop the machine, hand cut the thread with a knife, and then repeat the operation on the subsequent bags. For mass production techniques, cutting of the thread or string would require either an additional man on the line or necessitate the single operator to stop the sewing operation while he reached over to sever the thread.

It is, therefore, an object of this invention to provide an adapter for an industrial sewing machine wherein the thread may be automatically severed after the stitching is completed.

Another object of this invention is to provide an adapter for a sewing machine for automatically sewing the mouth of bags in mass production.

Another object of this invention is to provide an adapter for an industrial sewing machine wherein a line of bags conveyed therein will each automatically start the machine upon being fed against the adapter and both stop the machine together with automatically cutting the thread after a stitched closure has been formed on each.

Another object of this invention is to provide an industrial sewing machine adapter for automatically stitching bags and severing the thread after the sewn closure has been completed.

Other objects of this invention are to provide an improved device of the character described, that is easily and economically produced, which is sturdy in construction, and which is highly efdcient in operation.

With the above and related objects in view, this invention consists in the details of construction and combination of parts, as will be more fully understood from the following description, when read in conjunction with the accompanying drawing, in which:

FIG. 1 is a perspective View of an industrial sewing machine adapter embodying thisinvention.

FIG. 2 is a rear view of the adapter.

FIG. 3 to FIG. 6 inclusive are front views of the adapter showing successive stages of the operating cycle.

FIG. 7 is a schematic view of the wiring diagram embodied in this invention.

FIG. 8 is a perspective view of the thread depressor tongue assembly.

Referring now in greater detail to the drawing in which similar reference characters refer to similar parts, it shows a sewing machine adapter for stitch closing bags automatically comprising a frame, generally designated as A, an actuator, generally designated as B, vertically slidable in the frame, and a thread depressor, generally designated as C, tripped by said actuator for piunging the thread end against a cutting edge.

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A f we The frame A is mounted upon the head 10 of a sewing machine D and comprises a plate'lz having atfixed there'- to a switch box 14 on one face and a casing 16 on the other face. A sheath 18 extends downwardly from the box 14 and slidably retains the actuator B. The thread depressor C is axially guided within a plunger chute 20 downwardly projecting from the casing 16. The actuator B comprises a bar 22 slidably supported within the sheath 18 and a presser foot 24 pivotally mounted at the lower end of the bar. The presser foot 24 has a furcated portion 24A angled upwardly at the forward end thereof and a' notch 24B at the rear end. An uncinated portion 24C at the top of the presser foot engages the bar 22 and acts as a bar 22 projects into the interior of the switch box 14 and springs 26 resiliently urge the actuator B downwardly so that the foot 24 is forced toward the topof the working surface 28. Micro-switches 30 and 32 having spring loaded buttons with normally open contacts are mounted within the box 14 at opposite sides thereof and are wired to a solenoid 38 and a sewing machine motor 33 as shown in FIG. 7. The micro-switches 3t) and 32 are actuated respectively by earns 34 and 36 longitudinally spaced from eachother and disposed at opposite edges of the bar 22.

The depressor C comprises a plunger shaft 39 which is longitudinally slidable within the chute 20 and normally urged by a spring 40 to retreat upwardly therein. The upper end of the plunger shaft 39 is in engagement with the solenoid core whereby energizing the solenoid 38 will force the shaft downwardly against the bias of the spring 4i). The lower end of the shaft 39 has an oifset flange 42 thereon to which is afiixed a rod 44 having a tongue 46 at its bottom with a V-shaped notch 48. A guide flange 56 mounted upon the exterior of the chute 20 slidably retains the tongue 46 at right angles to the line being sewn upon bags E asthey are fed through the sewing machine D. The apex of the notch 48 is aligned with an automatically operated scissors device 52 and when the thread depressor C is actuated after bag E has been stitched closed, the thread or string will be urged into the scissors 52 by the tongue 46 and be automatically sheared.

As is apparent from the foregoing description, the invention operates as follows: Bags E lying on their sides and filled with contents but having open mouths are longitudinally transported in spaced relation on a conveyor (not shown) into the sewing machine D. A guide plate 54 having a beveled leading edge 54A defines a V-shaped guideway with the furcated portion 24A of the foot 24 whereby the mouth of the bags E will be forced closed. FIG. 3 shows the adapter in starting or finishing position wherein cam 34 engages the micro-switch 30 to energize the solenoid 33 and cause the thread depressor C to be in down position while the sewing machine motor 33 is inoperative.

As shown in FIG. 4, when a bag E first moves into the adapter, the foot 24 will move upward slightly so as to cause the cam 34- to elevate sufficiently and ride off from the micro-switch 30. In this position the solenoid 38 will become deenergized and the spring 46 will raise the thread depressor C. However, the sewing machine motor 33 will not have as yet been energized since cam 36 is not raised sufficiently to abut micro-switch 32. When the conveyor further urges the particular bag E so as to space the foot 24 appreciably above the working surface 28, the actuator B will be elevated sufficiently to cause the cam 36 to engage the micro-switch 32 and close the contacts thereof. See FIG. 5. The sewing machine motor 33 will then be energized so that a line of stitching will be sewn across the closed mouth of the bag E. The feed dog 53 in the base 28 of the sewing machine D as well as the stitching needle will now continue to operate until the rear edge of the bag reaches the notch 24B of the presser foot 24.

As shown in FIG. 6, the actuator B will be urged into a depressed position and the cam 34 will slide down from the micro-switch 32 causing the motor 33 to cut out. However, slight override of the motor will move the rear edge of the bag beyond the shear line of the tongue 46 on the thread depressor. When the bag E moves beyond the trailing end of the presser foot 24 as caused by the override, the actuator B will move into engagement with the Working surface 28 and the cam 34 will once more engage the micro-switch 30 so as to energize the solenoid 38. The thread depressor C will now be forced downwardly. The tongue 46 will engage the trailing edge of the thread and urge the thread into the scissors 52 and cause automatic shearing thereof. The position illustrating the end of the cycle preparation to initiating a new cycle is shown in FIG. 3.

Although this invention has been described in considerable detail, such description is intended as being illustrative rather than limiting, since the invention may be variously embodied, and the scope of the invention is to be determined as claimed.

What is claimed is:

1. In combination with a sewing machine including a working surface, an adapter comprising a frame affixed to the head of the sewing machine, an actuator slidable in said frame transversely to the working surface of said sewing machine and having a foot at the end toward said surface, resilient means biasing said actuator into engagement with said surface, said actuator being arranged to be moved away from said surface against its bias by passage of the object being sewn between said foot and said surface, a thread depressor slidable in said frame for movement paralleling said actuator, said thread depressor having at its bottom a tongue notched at the lower end and guided to maintain said tongue at right angles to the line of stitching, resilient means biasing said thread depressor away from said surface, thread severing scissors means on said sewing machine aligned with the path of travel of said tongue for thread severing engagement therewith, and solenoid means operable by movement of said actuator for moving said depressor against its bias to cut the trailing end of the thread automatically upon through passage of the sewn object.

2. The invention of claim 1 wherein said solenoid means includes two micro-switches, a solenoid for actuatingsaid depressor and operable by one of said microswitches, the other micro-switch adapted to start a motor for actuating the sewing machine and cams afiixed to said actuator in separable sequential slidable engagement with said micro-switches.

References Cited in the file of this patent UNITED STATES PATENTS 2,539,627 Kindseth et al J an. 30, 1951 2,630,086 Kindseth et al Mar. 3, 1953 2,707,927 Artzt et al May 10, 1955 

